SABR Defensive Index released: Parra is good, Corbin robbed

For the first time this year, the Gold Glove awards included some objective numbers as well as the subjective views of managers and coaches, in the shape of the SABR Defensive Index (SDI). While the stats were a minority weighting - about 25% of the votes - it was still a move in the right direction. That's particularly the cases, for an award which has previously been seen as going too much on previous reputation rather than actual performance, and also building in factors outside of what it's supposed to be about, such as offensive performance (hello, Carlos Gonzalez!). Here's what the SDI covers, taking from the SABR site:

The SABR Defensive Index draws on and aggregates two types of existing defensive metrics: those derived from batted ball location-based data and those collected from play-by-play accounts. The three metrics representing batted ball data include Defensive Runs Saved from Baseball Info Solutions, Ultimate Zone Rating developed by noted sabermetrician Mitchel Lichtman, and Runs Effectively Defended built by SABR Defensive Committee member Chris Dial. The two metrics included in the SDI originating from play-by-play data are Defensive Regression Analysis, created by committee member Michael Humphreys, and Total Zone Rating.

While the Gold Glove awards were released earlier in the week, today saw SABR announce the SDI results, which give us a figure for each player at the position (who met the Rawlings' minimum innings requirement). This figure represents the number of runs saved by that player, compared to league average at that position. It's interesting to compare the numbers for those who won the award, to the "best" players by the metric. Here's a run through of the various positions, and how the D-backs did:

• Pitcher. Patrick Corbin unjustly robbed of Gold Glove! That is the only conclusion possible here (okay, I might be viewing things through Sedona Red glasses somewhat), as Corbin's SDI of 4.9 was more than a run better than any other pitcher in the NL - suck it, Zack Greinke - and more than twice as good as actual winner, Adam Wainwright, who came eighth.
• Catcher.Miguel Montero ranked ninth out of 14. I'm actually somewhat surprised he ranked that high, given his problem with pitch blocking, though he still did throw out more base-stealers than average. Russell Martin edged actual Gold Glove winner Yadier Molina here, though the margin was less than 10%. The Rockies' Wilin Rosario was the worst defensive catcher in the NL. This is my shocked face.
  
• First base.The top three here were the nominees, Anthony Rizzo and Adrian Gonzalez joining winner Paul Goldschmidt. However, Rizzo and Goldie were streets ahead of A-Gon in SDI, both worth twice as much. Rizzo edged Goldschmidt, but only by a hair, 11.1 to 10.7: not that you'd know it was so close, from the petulant whining heard out of some Cubs fans at the decision.
• Second base. No D-backs worked enough to qualify here. Aaron Hill led the way, with 741 innings, but the time lost to a broken hand was sufficient to exclude him from consideration. Actual winner Brandon Phillips came top of the SDI ranking - though, the link cited above also contains bleating that Darwin Barney was also a victim of anti-Cubs hatred. Or something.
• Shortstop. I guess Didi Gregorius's tally, just shy of 900 innings, wasn't enough to qualify either - I'd have been interested to see where about he ranked. Gregorius certainly looked pretty good at the position, but UZR was considerably less impressed. No surprise as to the top spot here, Andrelton Simmon finishing over 20 runs better than the #2, and winning the Platinum Glove as a result
• Third base. Martin Prado finished seventh out of 13 qualifiers at this position, though with a positive score of +1.9. As with most of the infield positions, there wasn't much to argue about, the winner Nolan Arenado also coming top in SDI. He and the Dodgers' Juan Uribe were a long way ahead of the pack in the National League at this spot.
• Left field. It's probably for the best that our most-used left fielder wasn't listed, as his omission may well have spared Jason Kubel from further embarrassment. This spot had likely the biggest discrepancy between SDI and actual result, winner Carlos Gonzalez managing only +1.7, a long way behind league leader, the Pirates' Starling Marte, at +9.2.
  
• Center field. I'm not going to argue that A.J. Pollock should have won the Gold Glove - Carlos Gomez was entirely worthy of the honor there. However, you can certainly make a case he should have been nominated. His SDI of +8.8 was superior to both other nominees, Denard Span (+6.6) and Andrew McCutchen (+5.8), and they played 385 and 461 more innings respectively at the position.
• Right field. It is, of course, all about Gerardo Parra, whose SDI of +18.9 was fourth-best across the entire league, trailing Simmons, Gomez and Arenado. The Reds' Jay Bruce was the only other player in right to come within ten runs of Parra, and the third nominee, Jason Heyward, was also ranked third in SDI, so this was one where subjective and objective opinions appeared to line up.